This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Sox2, as well as many other transcription factors, are known to be O-GlcNAcylated. In order to better understand O-GlcNAcylation during pluripotency maintenance, one must be able to i) identify the low abudnace O-GlcNAcylated nuclear proteins involved without bias, ii) assign site-specific residues for O-GlcNAcylation and iii) understand from what cellular context the O-GlcNAc signal came, since many nuclear events come from extranuclear signals.